Multizone magnetron assembly

ABSTRACT

The present invention generally provides an apparatus and method for processing a surface of a substrate in physical vapor deposition (PVD) chamber that has a magnetron assembly that has separately positionable magnetron sections to improve the deposition uniformity. In general, aspects of the present invention can be used for flat panel display processing, semiconductor processing, solar cell processing, or any other substrate processing. In one aspect, the processing chamber contains one or more magnetron sections and magnetron actuators that are used to increase and more evenly distribute the magnetic field strength throughout the processing region of the processing chamber during processing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Patent Application Ser. No. 60/714,979, filed Sep. 7, 2005, which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to substrate plasma processing apparatuses and methods that are adapted to deposit a film on a surface of a substrate.

2. Description of the Related Art

Physical vapor deposition (PVD) using a magnetron is one of the principal methods of depositing metal onto a semiconductor integrated circuit to form electrical connections and other structures in an integrated circuit device. During a PVD process a target is electrically biased so that ions generated in a process region can bombard the target surface with sufficient energy to dislodged atoms from the target. The process of biasing a target to cause the generation of a plasma that causes ions to bombard and remove atoms from the target surface is commonly called sputtering. The sputtered atoms travel generally toward the wafer being sputter coated, and the sputtered atoms are deposited on the wafer. Alternatively, the atoms react with a gas in the plasma, for example, nitrogen, to reactively deposit a compound on the wafer. Reactive sputtering is often used to form thin barrier and nucleation layers of titanium nitride or tantalum nitride on the substrate.

Direct current (DC) magnetron sputtering is the most usually practiced commercial form of sputtering. The metallic target is biased to a negative DC bias in the range of about −100 to −600 VDC to attract positive ions of the working gas (e.g., argon) toward the target to sputter the metal atoms. Usually, the sides of the sputter chamber are covered with a shield to protect the chamber walls from sputter deposition. The shield is typically electrically grounded and thus provides an anode in opposition to the target cathode to capacitively couple the DC target power to the plasma generated in the sputter chamber.

A magnetron having at least a pair of opposed magnetic poles is typically disposed near the back of the target to generate a magnetic field close to and parallel to the front face of the target. The induced magnetic field from the pair of opposing magnets trap electrons and extend the electron lifetime before they are lost to an anodic surface or recombine with gas atoms in the plasma. Due to the extended lifetime, and the need to maintain charge neutrality in the plasma, additional argon ions are attracted into the region adjacent to the magnetron to form there a high-density plasma. Thereby, the sputtering rate is increased.

However, conventional sputtering presents challenges in the formation of advanced integrated circuits on large area substrates, such a flat panel display substrates. Typically, for TFT applications, the substrate is a glass substrate with a surface area greater than about 2000 cm². Commonly, TFT processing equipment is generally configured to accommodate substrates up to about 1.5×1.8 meters. However, processing equipment configured to accommodate substrate sizes up to and exceeding 2.16×2.46 meters, is envisioned in the immediate future. One issue that arises is that it is generally not feasible to create a chamber big enough to maintain the surface area ratio of the cathode (target) to anode surface area commonly used in conventional sputter processing chambers. Trying to maintain the surface area ratio can lead to manufacturing difficulties due to the large size of the parts required to achieve the desired area ratio and processing problems related to the need to pump down such a large volume to a desired base pressure prior to processing. The reduced surface area of the anode relative to the large target surface area generally causes the density of the plasma generated in the processing region, which is generally defined as the region below the target and above the substrate, to vary significantly from the center of the target to the edge of the target. Since the anodic surfaces are commonly distributed around the periphery of the target, it is believed that the larger distance from the center of the target to the anodic surfaces, makes the emission of electrons from the target surface at the edge of the target more favorable, and thus reduces the plasma density near the center of the target. The reduction in plasma density in various regions across the target face will reduce the number of ions striking the surface of the target in that localized area and thus varying the uniformity of the deposited film across the surface of a substrate that is positioned a distance from the target face. The insufficient anode area problem will thus manifest itself as a film thickness non-uniformity that is smaller near the center of the substrate relative to the edge.

Therefore, there is a need for a method and apparatus that can improve the uniformity of the PVD deposited film.

SUMMARY OF THE INVENTION

The present invention generally provides a plasma processing chamber assembly for depositing a layer on a substrate comprising a plasma processing chamber having a processing region, a target positioned on the plasma processing chamber so that a surface of the target is in contact with the processing region, a magnetron assembly positioned near the target, wherein the magnetron assembly comprises a magnetron section that has one or more magnets that are magnetically coupled to the processing region, and an actuator that is adapted to position the magnetron section in a direction generally perpendicular to the surface of the target, and a substrate support positioned inside the plasma processing region, wherein the substrate support is adapted to support a substrate on a substrate supporting surface.

Embodiments of the invention may further provide a plasma processing chamber assembly for depositing a layer on a substrate comprising a plasma processing chamber having a processing region, a target positioned on the plasma processing chamber so that a surface of the target is in contact with the processing region, a magnetron assembly positioned near the target, wherein the magnetron assembly comprises a first magnetron section that has one or more magnets that are magnetically coupled to the processing region, a second magnetron section that has one or more magnets that are magnetically coupled to the processing region, a first actuator that is adapted to position the first magnetron section in a direction generally perpendicular to the surface of the target, and a second actuator that is adapted to position the first magnetron section in a direction generally parallel to the surface of the target, and a substrate support positioned inside the plasma processing region, wherein the substrate support is adapted to support a substrate on a substrate supporting surface.

Embodiments of the invention may further provide a plasma processing chamber assembly for depositing a layer on a substrate comprising a plasma processing chamber having a processing region, a target positioned on the plasma processing chamber so that a surface of the target is in contact with the processing region, a magnetron assembly positioned near to the target, wherein the magnetron assembly comprises a first magnetron section that has one or more magnets that are magnetically coupled to the processing region, a second magnetron section that has one or more magnets that are magnetically coupled to the processing region, wherein the first magnetron section is nested within the second magnetron section, a first actuator that is adapted to position the first magnetron section in a direction generally perpendicular to the surface of the target, and a second actuator that is adapted to position the first magnetron section and the second magnetron section in a direction generally parallel to the surface of the target, and a substrate support positioned inside the plasma processing region, wherein the substrate support is adapted to support a substrate on a substrate supporting surface.

Embodiments of the invention may further provide a method of depositing a layer on a surface of a substrate, comprising providing a target that has a surface that contacts a processing region, providing a magnetron section that is magnetically coupled to the processing region through the target, depositing a conductive layer on a surface of a substrate that is positioned in the processing region, and adjusting the position the magnetron section in a direction generally perpendicular to the surface of the target to improve the deposition uniformity across the surface of the substrate.

Embodiments of the invention may further provide a method of depositing a layer on a surface of a substrate, comprising providing a target that has a surface that contacts a processing region, providing a magnetron section that is magnetically coupled to the processing region through the target, moving the magnetron section in a direction that is generally parallel to the surface of the target by use of an actuator, depositing a conductive layer on a surface of a substrate that is positioned in the processing region, and adjusting the position of the magnetron section in a direction generally perpendicular to the surface of the target while the magnetron is moving in a direction that is generally parallel to the surface of the target to improve the deposition uniformity across the surface of the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

FIG. 1 is a vertical cross-sectional view of conventional physical vapor deposition chamber.

FIG. 2 is a vertical cross-sectional view of an exemplary physical vapor deposition chamber.

FIG. 2B is a vertical cross-sectional view of a processing region formed in an exemplary physical vapor deposition chamber.

FIG. 3A schematically illustrates a plurality of magnetron sections positioned near a target in an exemplary physical vapor deposition chamber.

FIG. 3B illustrates a plot of magnetic field strength versus the distance along a path that extends across and through the center of a target that may be used in an exemplary physical vapor deposition chamber.

FIG. 3C schematically illustrates a plurality of magnetron sections positioned near a target in an exemplary physical vapor deposition chamber.

FIG. 3D illustrates a plot of magnetic field strength versus the distance along a path that extends across and through the center of a target that may be used in an exemplary physical vapor deposition chamber.

FIG. 4A is a plan view of a linear magnetron usable with the sputter reactor of FIG. 2.

FIG. 4B is a schematic plan view of a plasma loop formed by a serpentine magnetron according to one aspect of the invention.

FIG. 4C is a schematic plan view of a plasma loop formed by a rectangularized spiral magnetron according to one aspect of the invention.

FIG. 4D is a more realistic plan view of a serpentine magnetron according to one aspect of the invention.

FIG. 4E is a more realistic plan view of a rectangularized spiral magnetron according to one aspect of the invention.

FIG. 4F is a plan view of a magnetron assembly having two magnetron sections according to one aspect of the invention.

FIG. 4G is a vertical cross-sectional view of the magnetron assembly illustrated in FIG. 4F according to one aspect of the invention.

FIG. 4H is a plan view of a magnetron assembly having two magnetron sections according to one aspect of the invention.

FIG. 4I is a vertical cross-sectional view of the magnetron assembly illustrated in FIG. 4H according to one aspect of the invention.

FIG. 5 is a vertical cross-sectional view of a processing region formed in an exemplary physical vapor deposition chamber.

DETAILED DESCRIPTION

The present invention generally provides an apparatus and method for processing a surface of a substrate in a PVD chamber that has a magnetron assembly that has separately positionable magnetron sections to improve the deposition uniformity. In general, aspects of the present invention can be used for flat panel display processing, semiconductor processing, solar cell processing, or any other substrate processing. The invention is illustratively described below in reference to a physical vapor deposition system, for processing large area substrates, such as a PVD system, available from AKT, a division of Applied Materials, Inc., Santa Clara, Calif. In one embodiment, the processing chamber is adapted to process substrates that have a surface area of at least about 2000 cm². In another embodiment, the processing chamber is adapted to process substrates that have a surface area of at least about 19,500 cm² (e.g., 1300 mm×1500 mm). In one aspect, the processing chamber is adapted to process rectangular substrates. However, it should be understood that the apparatus and method may have utility in other system configurations, including those systems configured to process large area round substrates.

FIG. 1 illustrates a cross-sectional view of the processing region of a conventional physical vapor deposition (PVD) chamber 1. The conventional PVD chamber 1 generally contains a target 8, a vacuum chamber 2, an anode shield 3, a shadow ring 4, a target electrical insulator 6, a DC power supply 7, a process gas source 9, a vacuum pump system 11 and a substrate support 5. To perform a sputtering process, a process gas, such as argon, is delivered into the evacuated conventional PVD chamber 1 from the gas source 9 and a plasma is generated in the processing region 15 due to a negative bias created between the target 8 and the anode shield 3 by use of the DC power supply 7. In general, the plasma is primarily generated and sustained by the emission of electrons from the surface of the target due to the target bias and secondary emission caused by the ion bombardment of the negative (cathodic) target surface. Prior to performing the PVD processing step(s) it is common for the vacuum chamber 2 to be pumped down to a base pressure (e.g., 10⁻⁶ to 10⁻⁹ Torr) by use of the vacuum pump system 11.

FIG. 1 is intended to illustrate one of the believed causes of the plasma non-uniformity in a large area substrate processing chamber by highlighting the path difference between the an electron (see e⁻) ejected from the surface of the target 8 near the center of the target (see path “A”) and electrons emitted from the surface of the target (e.g., secondary emission) near the edge (see path “B”). While the longer path to the anode, typically a grounded surface, experienced by an electron leaving the center of the target may increase the number of collisions the electron will undergo before it is lost to the anode surface or recombined with an ion contained in the plasma, the bulk of the electrons emitted from the target 8 will be emitted near the edge of the target due to the reduced electrical resistance of this path to ground. The reduced electrical resistance of the path near the edge of the target to ground is due to the lower resistance path through the conductive target 8 material(s) and the shorter path length (“B”) of the electron's path to ground. It is believed that the lower resistance path thus tends to increase the current density and plasma density near the edge of the target thus increasing the amount of material sputtered at the edge versus the center of the target 8.

Increased Anode Area Hardware

FIG. 2 illustrates a vertical cross-sectional view of one embodiment of a processing chamber 10 that may be used to perform aspects of the invention described herein. In the configuration illustrated in FIG. 2, the processing chamber 10 contains a magnetron assembly 23 that has two or more magnetron sections 301 (e.g., elements 301A-301C in FIG. 2) that are used to increase and more evenly distribute a generated magnetic field throughout the processing region 15. FIG. 2 illustrates a substrate 12 that is positioned in a processing position in the processing region 15. In general, the processing chamber 10 contains a lid assembly 20 and a lower chamber assembly 35.

A. Lower Chamber Assembly Hardware

The lower chamber assembly 35 generally contains a substrate support assembly 60, chamber body assembly 40, a shield 50, a process gas delivery system 45 and a shadow frame 52. The shadow frame 52 is generally used to shadow the edge of the substrate to prevent or minimize the amount of deposition on the edge of a substrate 12 and substrate support 61 during processing (see FIG. 2). The chamber body assembly 40 generally contains one or more chamber walls 41 and a chamber base 42. The one or more chamber walls 41, the chamber base 42 and target 24 generally form a vacuum processing area 17 that has a lower vacuum region 16 and a processing region 15. In one aspect, a shield mounting surface 50A of the shield 50 is mounted on or connected to a grounded chamber shield support 43 formed in the chamber walls 41 to ground the shield 50. The process gas delivery system 45 generally contains one or more gas sources 45A that are in fluid communication with one or more inlet ports 45B that are in direct communication with the lower vacuum region 16 (shown in FIG. 2) and/or the processing region 15, to deliver a process gas that can be used during the plasma process. Typically, the process gas used in PVD type applications is, for example, an inert gas such as argon, but other gases such as nitrogen may be used.

The substrate support assembly 60 generally contains a substrate support 61, a shaft 62 that is adapted to support the substrate support 61, and a bellows 63 that is sealably connected to the shaft 62 and the chamber base 42 to form a moveable vacuum seal that allows the substrate support 61 to be positioned in the lower chamber assembly 35 by the lift mechanism 65. The lift mechanism 65 may contain a conventional linear slide (not shown), pneumatic air cylinder (not shown) and/or DC servo motor that is attached to a lead screw (not shown), which are adapted to position the substrate support 61, and substrate 12, in a desired position in the processing region 15. In one embodiment, the substrate support 61 may contain RF biasable elements 61A embedded within the substrate support 61 that can be used to capacitively RF couple the substrate support 61 to the plasma generated in the processing region 15 by use of an RF power source 67 and RF matching device 66. The ability to RF bias the substrate support 61 may be useful to help improve the plasma density, improve the deposition profile on the substrate, and increase the energy of the deposited material at the surface of the substrate.

Referring to FIG. 2, the lower chamber assembly 35 will also generally contain a substrate lift assembly 70, slit valve 46 and vacuum pumping system 44. The lift assembly 70 generally contains three or more lift pins 74, a lift plate 73, a lift actuator 71, and a bellows 72 that is sealably connected to the lift actuator 71 and the chamber base 42 so that the lift pins 74 can remove and replace a substrate positioned on a robot blade (not shown) that has been extended into the lower chamber assembly 35 from a central transfer chamber (not shown). The extended robot blade enters the lower chamber assembly 35 through the access port 32 in the chamber wall 41 and is positioned above the substrate support 61 that is positioned in a transfer position (not shown). The vacuum pumping system 44 (elements 44A and 44B) may generally contains a cryo-pump, turbo pump, cryo-turbo pump, rough pump, and/or roots blower to evacuate the lower vacuum region 16 and processing region 15 to a desired base and/or processing pressure. A slit valve actuator (not shown) which is adapted to position the slit valve 46 against or away from the one or more chamber walls 41 may be a conventional pneumatic actuator which are well known in the art.

To control the various processing chamber 10 components and process variables during a deposition process, a controller 101 is used. The processing chamber's processing variables may be controlled by use of the controller 101, which is typically a microprocessor-based controller. The controller 101 is configured to receive inputs from a user and/or various sensors in the plasma processing chamber and appropriately control the plasma processing chamber components in accordance with the various inputs and software instructions retained in the controller's memory. The controller 101 generally contains memory and a CPU which are utilized by the controller to retain various programs, process the programs, and execute the programs when necessary. The memory is connected to the CPU, and may be one or more of a readily available memory, such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, or any other form of digital storage, local or remote. Software instructions and data can be coded and stored within the memory for instructing the CPU. The support circuits are also connected to the CPU for supporting the processor in a conventional manner. The support circuits may include cache, power supplies, clock circuits, input/output circuitry, subsystems, and the like all well known in the art. A program (or computer instructions) readable by the controller 101 determines which tasks are performable in the plasma processing chamber. Preferably, the program is software readable by the controller 101 and includes instructions to monitor and control the plasma process based on defined rules and input data.

B. Lid Assembly and Magnetron Hardware

The lid assembly 20 generally contains a target 24, a lid enclosure 22, a ceramic insulator 26, one or more o-ring seals 29 and a magnetron assembly 23 that are positioned in a target backside region 21. In one aspect, the ceramic insulator 26 is not required to provide electrical isolation between the backing plate 24B of the target 24 and the chamber body assembly 40. In one aspect of the process chamber 10, a vacuum pump 25 (FIG. 2) is used to evacuate the target backside region 21 to reduce the stress induced in the target 24 due to the pressure differential created between the processing region 15 and the target backside region 21 during processing. The typically less than atmospheric pressure formed in the processing region 15 is created by use of the vacuum pumping system 44 (discussed below). The reduction in the pressure differential across the target 24 can be important for process chambers 10 that are adapted to process large area substrates greater than 2000 cm² to prevent the large deflections of the center of the target 24. Large deflections are often experienced even when the pressure differential is about equal to atmospheric pressure (e.g., 14 psi).

The sputter deposited film uniformity can be affected by the deflection, or bowing, of the target since it will cause the magnetic field strength generated by a conventional planar magnetron to vary from the center to the edge of a target 24 since the center of the target is moving a farther distance away from the conventional planar magnetron than the edge of the target and thus the magnetic field strength in the processing region 15 will be reduced in the center region of the target. The reduction in magnetic field strength will affect the plasma density uniformity across the target surface 24C and thus the sputter deposition profile on the processing surface of the substrate. To resolve this issue, embodiments of the invention utilize a magnetron assembly 23 that contain two or more magnetron sections (e.g., elements 301A-C) that are positionable relative to the target backside surface 24D, and thus the target surface 24C and processing region 15. In one embodiment, the magnetron assembly 23 will contain two or more magnetron sections (e.g., three shown in FIGS. 2 and 2B) that are positionable relative to the target surface 24C and each contain at least one magnet 27 that has a pair of opposing magnetic poles (i.e., north (N) and south (S)) that create a magnetic field (B-field) that passes through the target 24 and the processing region 15 (see element “B” in FIG. 2B). FIGS. 2 and 2B illustrates a cross-section of one embodiment of a processing chamber 10 that has one magnetron assembly 23 that contain three magnet sections (elements 301A-301C), which are positioned at the back of the target 24. It should be noted that while the target 24, illustrated in FIG. 2, has a backing plate 24B and target material 24A other embodiments of the invention may use a solid, or monolithic, type target without varying from the basic scope of the invention.

The magnetron sections 301 have an effect on the shape and uniformity of the PVD deposited layer due to the strength and orientation of the magnetic fields generated by the magnetron sections in the magnetron assembly 23. In general, each of the magnetron sections will contain at least one magnet 27. The magnets 27 may be permanent magnets (e.g., neodymium, samarium-cobalt, ceramic, or Alnico) or electromagnets. In one embodiment of the processing chamber 10, each magnetron section is adapted to deliver a constant or varying magnetic field strength using electromagnets as a function of time and/or position relative to the center of the target 24. In this configuration the single magnetron assembly 23 may contain two or more regions that have differing magnetic field strengths that are optimized to achieve a desired plasma density and sputter deposition profile. The term sputter deposition profile is intended to describe the deposited film thickness as measured across the substrate processing surface (element 12A in FIG. 2) of the substrate 12.

Referring to FIGS. 2 and 2B, in one embodiment of the processing chamber 10, the two or more magnetron sections (elements 301A-C) are distributed across the target 24 to balance out the difference in current flow between the center and edge of the target caused the differing resistance to the anode (e.g., ground) for each of these electrical paths. The control of the magnetic field distribution from the center to the edge of the target 24 is used to control and improve plasma density and thus the deposition uniformity across the processing surface. In one aspect, the magnetic field strength of the magnetron sections are configured to deliver a higher magnetic field strength in the center of the target 24 rather than the edge of the target. In one aspect, a higher magnetic field strength in the center of the target rather than the edge of the target is created by positing the magnetron sections near to the center of the target closer to the target surface 24C and/or moving the magnetron sections near the edge of the target away from the target surface 24C.

In one aspect, the magnetron assembly 23 is smaller in size than the target 24 and is translated across the back of the target 24 to assure full utilization of the target surface 24C. Referring to FIG. 2B, in one embodiment, to improve utilization of the target material and improve deposition uniformity the magnetron sections 301A-301C are translated (e.g., raster, scan, and/or rotate) in at least one of the directions (X and/or Y directions) that are parallel to the target surface 24C by use of one or more horizontal magnetron actuators 34A. In one aspect, where X and Y motion of one or more of the magnetron sections is desired two or more orthogonally oriented magnetron actuators 34A may be used to adjust the magnetron's position in the X-Y plane. The horizontal magnetron actuators 34A may be a linear motor, stepper motor, or DC servo motor that are adapted to position and move the magnetron assembly in a desired direction at a desired speed by use of commands from the controller 101. In one aspect, the horizontal actuators 34A may contain an independently controlled motor (e.g., linear motor, stepper motor, or DC servo motor) that is coupled to a worm gear, or lead screw, so that the coupled magnetron assembly 23 can be accurately positioned horizontally by commands from the controller 101. A translation mechanism that may be used to move the magnetron and be adapted to benefit the invention described herein is further described in the commonly assigned U.S. patent application Ser. No. 10/863,152 [AMAT 8841], filed Jun. 7, 2004, which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/534,952, filed Jan. 7, 2004, and U.S. patent application Ser. No. 10/863,152 [AMAT 8841.P1], filed Aug. 24, 2005, which are hereby incorporated by reference in its entirety to the extent not inconsistent with the claimed invention.

In another embodiment, the magnetron sections 301 are translated in at least one of the directions that are perpendicular (Z-direction) to the target surface 24C by use of one or more vertical magnetron actuators 34B. The ability to position a magnetron section (e.g., 301A, 301B, 301C) in a position perpendicular to the target surface 24C will affect the magnetic field strength formed in the processing region 15 and thus the plasma density in the regions below the target surface 24C. Generally, by moving the magnetron section(s) closer to the target 24 will increase the magnetic field strength in the processing region 15 while moving the magnet farther away from the target 24 will reduce the magnetic field strength passing through the processing region 15. Therefore, by adjusting the position of each of the magnetron sections (e.g., elements 301A-301C in FIG. 2B) relative to the target surface 24C, the plasma density and sputter deposition profile across the processing surface 12A can be varied or adjusted. In one aspect, the vertical position of a magnetron section is adjusted to compensate for the bow of the target 24. In another aspect, the vertical position of a magnetron section 301 (e.g., 301A, 301B, 301C) is adjusted during processing to compensate for the deposition non-uniformity found in the substrate surface. The vertical magnetron actuators 34B may be a linear motor, stepper motor, or DC servo motor that are adapted to position and move the magnetron assembly in a desired direction at a desired acceleration and/or speed by use of commands from the controller 101. In one aspect, the vertical actuators 34B may contain an independently controlled motor (e.g., linear motor, stepper motor, or DC servo motor) that is coupled to a worm gear, or lead screw, so that the coupled magnetron sections 301 can be accurately positioned by commands from the controller 101.

In one embodiment, the position of the magnetron sections 301 can be adjusted in the X, Y and Z directions (FIG. 2B) as a function of time or position relative to the center of the target 24 by the coordination of the horizontal and vertical magnetron actuators 34A-B by use of the controller 101. The ability to adjust the magnetron section 301 position in the X, Y and Z directions can be useful to adjust and/or tune the magnetic field strength in the processing region 15 and thus the sputter deposition profile received on the processing surface 12A of the substrate 12. In one aspect, each of the magnetron sections 301A-C are adapted to translate across the target 24 in unison by use of magnetron actuators 34A-B to control plasma density uniformity and improve the deposition profile across the substrate surface by use of the controller 101. In another aspect, each of the magnetron sections 301A-B are adapted to separately translated relative to the target 24 by use of one or more magnetron actuators (element 34A-B) and the controller 101.

FIGS. 3A and 3C schematically illustrate a target 24 that has three magnetron sections (elements 301A-C) that are each adapted to control the magnetic field strength in various regions of the target 24 during processing. The magnetron section 301A is thus adapted to control the magnetic field strength near the center of the target 24 and the magnetron sections 301B-C are adapted to control the magnetic field strength near the edge of the target 24. In one aspect, the magnetic field strength can be adjusted in each of target sections by use of stronger magnets in different regions of the magnetron section 301, increasing the density of the magnets in different regions of the magnetron section 301, using electromagnets that allow one to adjust the delivered magnetic field, and/or increasing the dwell time of each of the magnetron sections 301 over the certain areas of the target as the magnetron is translated in the X, Y and/or Z directions during processing by use of the magnetron actuators 34A-B.

FIGS. 3B and 3D illustrate a plot of magnitude of the magnetic field as a function of linear distance across the target 24 (in FIG. 3A or 3C). The magnetic field strength in these plots may be generated by the static placement of magnets across the target sections, the time average of the magnetic field strength caused by the translation of the magnetron sections 301 (e.g., elements 301A-C) across the target 24, and/or the varying of the magnetic field strength by adjusting the current delivered to the one or more electromagnets in the magnetron sections 301. The plots shown in FIGS. 3B and 3D illustrate the magnitude of the magnetic field in a linear path that extends from one edge (element “E”) of the target 24 through the center (element “C”) point of the target 24 and out to the opposite edge (element “E”) of the target 24.

FIGS. 3B and 3D, also generally illustrate an “edge region”, which is generally defined as an area of the target near the edge “E” of the target, and a “center region”, which is generally defined as an area of the target that is positioned over the center “C” of the target. The edge and center regions are generally areas over which one or more magnetron sections are adapted to move to achieve the desired magnetic field strength profile across the target surface in the X and Y-directions. For example, as shown in FIGS. 3A and 3B the center magnetron section 301A is generally adapted to be moved across the center section and edge magnetrons 301B, 301C are generally adapted to be moved across their respective edge sections. In some cases overlap of each magnetron into adjacent regions may be desirable to assure desirable process results (e.g., improved target utilization). The size and shape of the edge and center regions may be adjusted to improve the deposition uniformity and may vary depending on the magnetic field strength, dwell time of the magnetron sections over each region, and other typical sputter process variables.

FIG. 3B illustrates an exemplary distribution of the magnetic field strength (elements 131A-B) across the target (see FIG. 3A) measured just below the target surfaces 24C in the processing region 15. As shown the magnetic field strength varies linearly from the edge of the target 24 and peaks at the center of the target 24. In this configuration the larger magnetic field strength in the center target 24 will tend to increase the plasma density in the center versus the edge of the target and thus can be used to improve the sputter deposition profile when used in large area substrate processing chambers. In one example, the magnetic field strength variation from the center of the target to the edge for a process chamber adapted to process a 2.2 m×2.5 m substrate is configured to deliver about 0 to about 500 gauss near the edge to about 300 to about 1000 gauss near the center of the target 24.

FIG. 3D illustrates an exemplary distribution of the magnetic field strength (elements 131A-B) across the target (see FIG. 3C) measured just below the target surfaces 24C in the processing region 15. As shown in FIG. 3D the magnetic field strength is constant in different regions of the target 24, and the magnetic field strength has a discontinuity at the transitions between the different regions of the target. In this configuration the larger magnetic field strength in the center of the target will tend to increase the plasma density in the center versus the edge of the target 24 and thus can be used to improve the deposition profile.

Referring to FIGS. 3B and 3D, while the graphs of magnetic field strength across the target 24 are shown to vary in a linear fashion from the center to the edge of the target, other embodiments of the invention may use second degree (e.g., quadratic), third degree (e.g., cubic), exponential, or other shaped curves that delivers a desired the plasma density across the target face and desired sputter deposition profile without deviating from the basic scope of the invention described herein. Also, while FIGS. 3B and 3D illustrate the magnetic field strength across the target 24, which peak at the center (“C”) of the target 24, this configuration is not intended to be limiting to basic scope of the invention. Furthermore, while FIGS. 3B and 3D illustrate a magnetic field strength plot that varies in two main target sections (e.g., center and edge), other configurations may be used that contain an optimized magnetic field strength profile that contains multiple segments of changing magnetic field strength without varying form the basic scope of the invention as described herein.

In one embodiment, the magnets 27 in the magnetron sections (elements 301A-C) are electromagnets that may be translated or remain stationary over the target section(s) during processing. In one aspect, the magnetic field (B-Field) generated by the electromagnets can be dynamically adjusted during different phases of the deposition process, by adjusting the current passing through the plurality conductive coils contained in the electromagnet. In another aspect, the magnetic field generated by the electromagnets (element 27) can be dynamically adjusted as a function of position of the magnetron section 301 over its target 24. For example, the magnetron assembly's magnetic field strength may be reduced as magnetron section 301 is translated to positions that are near an edge of a target 24 (element “E”) to reduce the interaction between the adjacent magnetron sections or other chamber components. The ability to adjust the magnetic field strength as a function of translational position can help to improve the deposition uniformity and reduce the interaction between the various target sections.

To perform a PVD deposition process, the controller 101 commands the vacuum pumping system 44 to evacuate the processing chamber 10 to a predetermined pressure/vacuum so that the plasma processing chamber 10 can receive a substrate 12 from a system robot (not shown) mounted to a central transfer chamber (not shown) which is also under vacuum. To transfer a substrate 12 to the processing chamber 10 the slit valve (element 46), which seals off the processing chamber 10 from the central transfer chamber, opens to allow the system robot to extend through the access port 32 in the chamber wall 41. The lift pins 74 then remove the substrate 12 from the extended system robot, by lifting the substrate from the extended robot blade (not shown). The system robot then retracts from the processing chamber 10 and the slit valve 46 closes to isolate the processing chamber 10 from the central transfer chamber. The substrate support 61 then lifts the substrate 12 from the lift pins 74 and moves the substrate 12 to a desired processing position below the target 24. The position of the magnetron sections 301 may then be adjusted or continually varied as a function of time in the X, Y and/or Z directions to achieve a desired magnetic field in the processing region 15. Then after a achieving a desired base pressure, a desired flow of a processing gas is injected into the processing region 15 and a bias voltage is applied to the target 24 by use of a power supply 28 to generate a plasma in the processing region 15. The application of a DC bias voltage by the power supply 28 causes the gas ionized in the processing region 15 to bombard the target surface and thus “sputter” metal atoms that land on the processing surface 12A of the substrate positioned on the surface of the substrate support 61.

Magnetron Sections

FIG. 4A illustrates a plan view of a magnetron section 224 that has two poles 228 and 226 which are typically positioned parallel to the front face of the target 24 (FIG. 2B). In one aspect, as shown in FIG. 4A, the magnetron assembly 23 may be formed by a central pole 226 of one magnetic polarity surrounded by an outer pole 228 of the opposite polarity to project a magnetic field within the processing region 15 of chamber 10 (FIG. 2B). The two poles 226, 228 are separated by a substantially constant gap 230 over which a high-density plasma is formed under the correct chamber conditions and gas flows in a closed loop or track region. The outer pole 228 consists of two straight portions 232 connected by two semi-circular arc portions 234. The magnetic field formed between the two poles 226, 228 traps electrons and thereby increases the density of the plasma and as a result increases the sputtering rate. The relatively small widths of the poles 226, 228 and of the gap 230 produce a high magnetic flux density. The closed shape of the magnetic field distribution along a single closed track forms a plasma loop generally following the gap 230 and prevents the plasma from leaking out the ends of the formed plasma. In one aspect, it may not be desirable to form a closed shape of the magnetic field distribution. During the PVD deposition process a large portion of the generated plasma in the processing region 15 is formed and is retained below the magnetron assemblies 23 in the plasma loop due to the magnetic fields (elements “B” in FIG. 2B) containment of the electrons found in the processing region 15. The optimum shape of the generated plasma will vary from one substrate size to another, from the ratio of the anode (e.g., grounded surface) to cathode (e.g., target) surface area, target to substrate spacing, PVD process pressure, motion of the magnetron across the target face, desired deposition rate, and type of material that is being deposited. The effectiveness of the magnetron assembly 23 on reducing the center to edge deposited thickness variation is affected by the magnetic permeability of the target material(s) and the translation of the magnetron assembly 23. Therefore, in some case the magnetron magnetic field pattern may need to be adjusted based on the type of target 24 material(s) and their thickness(es).

In one embodiment, as illustrated in FIG. 4A, at least one of the magnetron sections 301 are formed using a central pole and outer pole that have a convoluted shape rather than a linear shape. FIGS. 4B and 4C schematically illustrates the shape of a plasma loop 245 created in the processing region 15 of a plasma processing chamber below a target 242, which is formed using two different convoluted magnetron section shapes that will hereafter be described as a serpentine magnetron 240 (FIG. 4B) or spiral magnetron 250 (FIG. 4C). Referring to FIG. 4B, to form the plasma loop 245 the serpentine magnetron 240 will generally include multiple long parallel straight portions 243 that are joined by end portions 244. The end portions 244 may be arc shaped or alternatively short straight portions with curved corners connecting them to the straight portions 243. The effective area of the serpentine magnetron 240 defined by the outer generally rectangular outline of the magnetic field distribution parallel to the target face is a substantial fraction of target area. Referring to FIG. 4C, in a related embodiment, a plasma loop 245 may be formed using a spiral magnetron 250 that includes a series of straight portions 252 and 254 that extend along perpendicular axes and are smoothly joined together to form a plasma loop that has a rectangular spiral shape.

The plasma loop formed by the magnetron shapes illustrated in FIGS. 4B and 4C are intended to be a schematic representation of some magnetron section configurations that may be useful to perform various aspects of the invention described herein. One will note that the number of folds and the distance between the plasma loops in either magnetron 240, 250 may be significantly adjusted as required to achieve a desired process uniformity or deposition profile. Although it is not necessary, each of the magnetrons may be considered a folded or twisted version of an extended racetrack magnetron of FIG. 4A with a plasma loop formed between the inner pole and the surrounding outer pole.

FIGS. 4D and 4E illustrate a serpentine magnetron assembly 260 (FIG. 4D) and spiral magnetron assembly 270 (FIG. 4E), that are closed convoluted magnetron shapes that are useful to perform aspects of the invention described herein. In one aspect, one or more of the magnetron sections (e.g., elements 301A-B) may contain a serpentine or spiral magnetron assembly. FIG. 4D schematically illustrates one embodiment of a serpentine magnetron assembly 260 that has an array of magnets (e.g., hatched circles) that are aligned and arranged in grooves 264A-B formed in the magnetron plate 263 to form a first pole 261 and a second pole 262. The two opposing poles, such as first pole 261 and the second pole 262, form a magnetic field in the gaps 265 formed between the first pole 261 and second pole 262. In one aspect, the serpentine magnetron assembly 260, as illustrated in FIG. 4D, is formed using an array of magnets 27 that are oriented so that the first pole 261 forms the north pole (elements “N”) of the serpentine magnetron assembly and the second pole 262 forms the south pole (elements “S”) of the serpentine magnetron assembly. Generally, the magnets 27 described herein may be permanent magnets (e.g., neodymium, samarium-cobalt, ceramic, or Alnico) or electromagnets. In one aspect, not shown, the width of the outer grooves 264A, which are at the edge of the serpentine magnetron assembly is generally about half the widths of the inner grooves 264B since the outer grooves 264A accommodate only a single row of magnets while the inner groove 264B accommodate two rows of magnets (not shown) in a staggered arrangements to balance the generated magnetic field strength between the poles. In one aspect, a single magnetic yoke plate (not shown) may cover the back of the magnetron plate 263 to magnetically couple the poles of all the magnets. In one aspect, the magnets positioned in grooves 264A and 264B are capped with their respective pole pieces that are typically formed of magnetically soft stainless steel and have a shape and width that is approximate equal to the formed grooves 264A or 264B.

FIG. 4E illustrates one embodiment of a spiral magnetron assembly 270 that has an array of magnets (e.g., hatched circles) that are aligned and arranged in grooves 274A-B formed in the magnetron plate 273 to form a first pole 271 and a second pole 272. The two opposing poles, such as first pole 271 and the second pole 272, form a magnetic field in the gaps 275 formed between the first pole 271 and second pole 272. In one aspect, the spiral magnetron assembly 270, as illustrated in FIG. 4F, is formed using an array of magnets that are oriented so that the first pole 271 forms the north pole (elements “N”) of the spiral magnetron assembly and the second pole 272 forms the south pole (elements “S”) of the spiral magnetron assembly. The width of the outer grooves 274A, which are at the edge of the spiral magnetron assembly is generally about half the widths of the inner grooves 274B since the outer grooves 274A accommodate only a single row of magnets while the inner groove 274B accommodate two rows of magnets (not shown) in a staggered arrangements to balance the generated magnetic field strength between the poles. In one aspect, a single magnetic yoke plate may cover the back of the magnetron plate 273 to magnetically couple the poles of all the magnets. In one aspect, the magnets 27 positioned in grooves 274A and 274B are capped with their respective pole pieces that are typically formed of magnetically soft stainless steel and have a shape and width that is approximate equal to the formed grooves 274A or 274B.

FIG. 4F illustrates plan view of one embodiment of a magnetron assembly 23 that have two magnetron sections 301A and 301B. In this configuration the first magnetron sections 301A is nested within the second magnetron section 301B and a gap 302 is formed between the two magnetron sections. In one aspect, as shown in FIG. 4F, the first magnetron section 301A has a serpentine magnetron assembly 260 arrangement of magnets and the second magnetron section 301B has a spiral magnetron assembly 270 arrangement of magnets. One will note that the outer pole 272 in the second magnetron section 301B and the outer pole 262 in the first magnetron section 301A are schematically illustrated as dashed lines, and the inner pole 271 in the second magnetron section 301B and the inner pole 261 in the first magnetron section 301A are schematically illustrated as solid lines.

FIG. 4G schematically illustrates a side cross-sectional view of the magnetron assembly 23 shown in FIG. 4F that is contained in the target backside region 21 of the lid assembly 20 (FIG. 2) and near the target 24. In one embodiment, as shown in FIG. 4G, the magnetron assembly 23 is supported and/or coupled to a support plate 303. In this configuration the vertical magnetron actuators (e.g., 34B′ and 34B) are coupled to support plate 303 and their respective magnetron section (e.g., 301A or 301B) to vertically position (Z-direction) the magnetron sections relative to the target surface 24C. In one aspect, the first magnetron section 301A is adapted to move a distance “A” closer to the target surface 24C than the second magnetron section 301B. In one aspect, the distance “A” may be about 5 mm. In embodiment, as shown in FIG. 4G, one or more horizontal magnetron actuators 34A are adapted to translate the support plate 303, and coupled magnetron sections 301A-B, in the X and/or Y directions. As noted above, the vertical magnetron actuators 34B and horizontal actuators 34A may be a linear motor, stepper motor, or DC servo motor that are adapted to position and move the magnetron assembly in a desired direction at a desired acceleration and/or speed by use of commands from the controller 101. An example of actuators that may be adapted to perform the vertical magnetron actuators (e.g., 34B′ and 34B) and horizontal magnetron actuators 34A are further described in the commonly assigned U.S. patent application Ser. No. 10/863,152 [AMAT 8841.P1], filed Aug. 24, 2005, which is hereby incorporated by reference in its entirety to the extent not inconsistent with the claimed invention.

FIG. 4H illustrates a plan view of one embodiment of a magnetron assembly 23 that have two magnetron sections 301A and 301B. In this configuration the first magnetron sections 301A is nested within the second magnetron section 301B and a gap 302 is formed between the two magnetron sections. In one aspect, as shown in FIG. 4H, the first and second magnetron sections 301A-B utilize a spiral magnetron assembly 270 magnet arrangement. One will note that the outer pole 272 in the second magnetron section 301B and the outer pole 272 in the first magnetron section 301A are schematically illustrated as dashed lines, and the inner pole 271 in the second magnetron section 301B and the inner pole 271 in the first magnetron section 301A are schematically illustrated as solid lines.

FIG. 41 schematically illustrates a side cross-sectional view of the magnetron assembly 23 shown in FIG. 4H that is contained in a lid assembly 20 (FIG. 2) near the target 24. In one embodiment, as shown in FIG. 41, the magnetron assembly 23 is supported and/or coupled to a support plate 303. In the configuration shown in FIG. 41, the second magnetron section 301B is mounted to the support plate 303 and the first magnetron section 301A is coupled to the magnetron plate 303 through the vertical magnetron actuator 34B′ to vertically position the magnetron section 301A relative to second magnetron section 301B and the target surface 24C. In one aspect, the first magnetron section 301A is adapted to move a distance “B” closer to the target surface 24C. In one aspect, the distance “B” may be about 5 mm. In embodiment, as shown in FIG. 41, one or more horizontal magnetron actuators 34A are adapted to translate the support plate 303, and coupled magnetron sections 301A-B, in the X and/or Y directions. In one embodiment, a second vertical magnetron actuator (not shown) is adapted to position the support plate 303 vertically and thus vertically position the first and second magnetron sections 301A-B.

Coordinated Motion

In one embodiment, the position of a magnetron section (e.g., 301A-B) in the Z-direction is adjusted relative to its position in the X-direction and/or Y-direction to account for the bow of the target 24, or just to adjust the deposition uniformity. For example, referring to FIG. 3A, the position in the Z-direction of the magnetron section 301A may be vertically lower (i.e., closer to an un-bowed target 24) as the magnetron section is moved across the center “C” of the target versus when the magnetron section 301A is positioned a distance away from the center “C” of the target in the X or Y-directions.

FIG. 5 schematically illustrates a vertical cross-sectional view of processing chamber 10 that has target 24 that is bowed and a magnetron assembly 23. The target 24, as noted above, may be bowed due to a pressure differential between the processing region 15 and the target backside region 21 and due to the distributed weight of the target, which thus causes the target to deflect relative to its original undeflected shape (element “E”). One will note that only a single magnetron section 301A is shown in FIG. 5 for simplicity and clarity, and that this configuration is not intended to be limiting as to the scope of the invention. In this configuration the magnetron section 301A is supported and positioned in the Z-direction by use of a vertical actuator 34B′, a support plate 303 and one or more supporting rollers 401 that are adapted to carry the weight of the magnetron assembly 23 and allow motion in the X and/or Y-directions. The magnetron section 301A may be positioned in the X and Y-directions by use of one or more horizontal actuators 34A. To achieve a desired magnetic field strength in the processing region 15, and thus a desired deposition uniformity, it may be desirable to continuously control the position of one or more of the magnetron sections (e.g., 301A shown in FIG. 5) in the X, Y and Z-directions during processing. A typical method of monitoring and controlling the position and motion of the one or more magnetron sections is to use a closed loop control scheme that utilizes encoders, or other similar devices, that are attached to each actuator and communicate with the controller 101. Therefore, in one embodiment, it is desirable to assure that a user-defined gap “G” (FIG. 5) is maintained between a magnetron section (e.g., 301A) and the target backside surface 24D of a target 24 that has a bowed surface. The user-defined gap, for example, may be between about 0.5 mm and about 10 mm.

In one embodiment, it may be desirable to define one or more desired trajectory paths (element “D” in FIG. 5) along which one or more of the magnetron sections (e.g., element 301A) follow as the magnetron assembly 23 is translated by use of the controller 101, the horizontal magnetron actuator(s) 34A and/or vertical magnetron actuator(s) 34B. In this configuration the controller 101 monitors and controls the position of one or more of the magnetron sections by coordinating and controlling the position magnetron section by use of the horizontal magnetron actuator(s) 34A and vertical magnetron actuator(s) 34B. The trajectory path may be empirically defined, derived from modeling, or calculated so that a desired deposition profile and/or deposition uniformity is achieved on the substrate surface. In one aspect, the trajectory path may be optimized to achieve a desired magnetic field strength in the processing region 15 and deposition profile on the surface of the processed substrate, and thus may not coincide with the bowed shape of the target 24.

While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. 

1. A plasma processing chamber assembly for depositing a layer on a substrate comprising: a plasma processing chamber having a processing region; a target positioned on the plasma processing chamber so that a surface of the target is in contact with the processing region; a magnetron assembly positioned near the target, wherein the magnetron assembly comprises: a magnetron section that has one or more magnets that are magnetically coupled to the processing region; and an actuator that is adapted to position the magnetron section in a direction generally perpendicular to the surface of the target; and a substrate support positioned inside the plasma processing region, wherein the substrate support is adapted to support a substrate on a substrate supporting surface.
 2. The plasma processing chamber assembly of claim 1, the substrate support is adapted to support a substrate that has a processing surface that has a surface area of at least 19,500 cm².
 3. The plasma processing chamber assembly of claim 1, further comprising an actuator that is adapted to position the magnetron section in a direction generally parallel to the surface of the target.
 4. The plasma processing chamber assembly of claim 1, wherein the magnetron section has a first pole and a second pole that is magnetically coupled to the processing region through the target, wherein the first pole and the second pole are adapted to form a plasma loop that has a serpentine shape.
 5. The plasma processing chamber assembly of claim 1, wherein the magnetron section has a first pole and a second pole that is magnetically coupled to the processing region through the target, wherein the first pole and the second pole are adapted to form a plasma loop that has a spiral shape.
 6. A plasma processing chamber assembly for depositing a layer on a substrate comprising: a plasma processing chamber having a processing region; a target positioned on the plasma processing chamber so that a surface of the target is in contact with the processing region; a magnetron assembly positioned near the target, wherein the magnetron assembly comprises: a first magnetron section that has one or more magnets that are magnetically coupled to the processing region; a second magnetron section that has one or more magnets that are magnetically coupled to the processing region; a first actuator that is adapted to position the first magnetron section in a direction generally perpendicular to the surface of the target; and a second actuator that is adapted to position the first magnetron section in a direction generally parallel to the surface of the target; and a substrate support positioned inside the plasma processing region, wherein the substrate support is adapted to support a substrate on a substrate supporting surface.
 7. The plasma processing chamber assembly of claim 6, the substrate support is adapted to support a substrate that has a processing surface that has a surface area of at least 19,500 cm².
 8. The plasma processing chamber assembly of claim 6, further comprising a third actuator that is adapted to position the second magnetron section in a direction generally perpendicular to the surface of the target.
 9. The plasma processing chamber assembly of claim 6, wherein the first magnetron section has a first pole and a second pole that is magnetically coupled to the processing region through the target, wherein the first pole and the second pole are adapted to form a plasma loop that has a serpentine shape.
 10. The plasma processing chamber assembly of claim 6, wherein the first magnetron section has a first pole and a second pole that is magnetically coupled to the processing region through the target, wherein the first pole and the second pole are adapted to form a plasma loop that has a spiral shape.
 11. The plasma processing chamber assembly of claim 6, wherein the second actuator is also adapted to position the second magnetron section in a direction parallel to the target surface.
 12. The plasma processing chamber assembly of claim 6, wherein the first magnetron section is positioned over a center region of the target and the second magnetron section is positioned of an edge region, wherein the magnetic field strength delivered by at least a portion of the first magnetron section to the processing region is greater than the magnetic field strength delivered by the second magnetron section to the processing region.
 13. A plasma processing chamber assembly for depositing a layer on a substrate comprising: a plasma processing chamber having a processing region; a target positioned on the plasma processing chamber so that a surface of the target is in contact with the processing region; a magnetron assembly positioned near to the target, wherein the magnetron assembly comprises: a first magnetron section that has one or more magnets that are magnetically coupled to the processing region; a second magnetron section that has one or more magnets that are magnetically coupled to the processing region, wherein the first magnetron section is nested within the second magnetron section; a first actuator that is adapted to position the first magnetron section in a direction generally perpendicular to the surface of the target; and a second actuator that is adapted to position the first magnetron section and the second magnetron section in a direction generally parallel to the surface of the target; and a substrate support positioned inside the plasma processing region, wherein the substrate support is adapted to support a substrate on a substrate supporting surface.
 14. The plasma processing chamber assembly of claim 13, the substrate support is adapted to support a substrate that has a processing surface that has a surface area of at least 19,500 cm².
 15. The plasma processing chamber assembly of claim 13, further comprising a third actuator that is adapted to position the second magnetron section in a direction generally perpendicular to the surface of the target.
 16. The plasma processing chamber assembly of claim 13, wherein the first magnetron section has a first pole and a second pole that is magnetically coupled to the processing region through the target, wherein the first pole and the second pole are adapted to form a plasma loop that has a serpentine shape.
 17. The plasma processing chamber assembly of claim 13, wherein the first magnetron section has a first pole and a second pole that is magnetically coupled to the processing region through the target, wherein the first pole and the second pole are adapted to form a plasma loop that has a spiral shape.
 18. The plasma processing chamber assembly of claim 13, wherein the second magnetron section has a first pole and a second pole that is magnetically coupled to the processing region through the target, wherein the first pole and the second pole are adapted to form a plasma loop that has a spiral shape.
 19. The plasma processing chamber assembly of claim 13, wherein the first magnetron section is positioned over a center region of the target and the second magnetron section is positioned of an edge region, wherein the magnetic field strength delivered by at least a portion of the first magnetron section to the processing region is greater than the magnetic field strength delivered by the second magnetron section to the processing region.
 20. A method of depositing a layer on a surface of a substrate, comprising: providing a target that has a surface that contacts a processing region; providing a magnetron section that is magnetically coupled to the processing region through the target; depositing a conductive layer on a surface of a substrate that is positioned in the processing region; and adjusting the position the magnetron section in a direction generally perpendicular to the surface of the target to improve the deposition uniformity across the surface of the substrate.
 21. The method of claim 20, further comprising: providing a second magnetron section that is magnetically coupled to the processing region through the target; and adjusting the position the second magnetron section in a direction generally perpendicular to the surface of the target to improve the deposition uniformity across the surface of the substrate.
 22. The method of claim 20, wherein the step of adjusting the position the magnetron section in a direction generally perpendicular to the surface of the target is continually controlled by use of a controller and an actuator.
 23. A method of depositing a layer on a surface of a substrate, comprising: providing a target that has a surface that contacts a processing region; providing a magnetron section that is magnetically coupled to the processing region through the target; moving the magnetron section in a direction that is generally parallel to the surface of the target by use of an actuator; depositing a conductive layer on a surface of a substrate that is positioned in the processing region; and adjusting the position of the magnetron section in a direction generally perpendicular to the surface of the target while the magnetron is moving in a direction that is generally parallel to the surface of the target to improve the deposition uniformity across the surface of the substrate.
 24. The method of claim 23, further comprising: providing a second magnetron section that is magnetically coupled to the processing region through the target; moving the second magnetron section in a direction that is generally parallel to the surface of the target by use of the actuator; and adjusting the position of the second magnetron section in a direction generally perpendicular to the surface of the target while the second magnetron is moving in a direction that is generally parallel to the surface of the target to improve the deposition uniformity across the surface of the substrate.
 25. The method of claim 23, further comprising: providing a second magnetron section that is magnetically coupled to the processing region through the target; moving the second magnetron section in a direction that is generally parallel to the surface of the target by use of a second actuator; and adjusting the position of the second magnetron section in a direction generally perpendicular to the surface of the target while the second magnetron is moving in a direction that is generally parallel to the surface of the target to improve the deposition uniformity across the surface of the substrate.
 26. The method of claim 23, wherein the step of adjusting the position the magnetron section is continually controlled by use of a controller and an actuator. 